Duplicating printing device



Aug. 21, 1962 B. s. KOBRlN DUPLICATING PRINTING DEVICE Filed Oct. 3, 1960 FIG.3

INVENTOR. Bernard 5. Kobrin G g M661 ATTORNEY United States atet 3,049,993 DUPLICATING PRINTING DEVICE Bernard S. Kobrin, 552 7th Ave., Bronx, N.Y. Filed Oct. 3, 1960, Ser. No. 60,059 1 Claim. (Cl. 101-127.1)

This invention relates to a method and apparatus for printing on cloth or other bases, and more particularly, concerns methods and apparatus for printing which involve the use of stencil sheets.

Silk screen printing, which is applicable to both paper and cloth bases, has a number of disadvantages. Thus, each fabric screen design must be stretched and retained on its own frame. When carrying an inventory of a large number of different designs, the storage space requirement-for the frames and their associated screen designs becomes substantial.

Also, when changing colors with a silk screen, the screen must be thoroughly washed to remove the previous color used. The necessary preliminary preparation of screens in multicolor operations, reduce the overall efiiciency of the printing operation.

Furthermore, silk screens as conventionally used, have a tendency toward flushing in the applied color, causing poor results in printing which involves very fine effects.

Accordingly, one object of this invention is to provide an improved printing procedure wherein a non-fibrous stencil sheet is adapted to be removably stretched on a frame during the printing operation, such stencil being quickly removed from the frame when not required; the unused stencils being storable fiat in minimum storage space.

Another object of this invention is to provide an improved printing procedure using a plastic stencil which may be quickly wiped cleaned when passing from one color to another, allowing for maximum efiiciency in multicolor printing operations.

Another object of this invention is to provide a duplicating process for imprinting fabrics with selected color designs, the imprinted fabric having the hand of roller printed fabrics, without additional processing.

A further object of this invention is to provide an improved printing procedure based on the use of an electrically perforated stencil of synthetic plastic; such stencil being detachably mounted in a frame while stretched in one direction only.

Still another object of this invention is to provide an improved method of printing wherein a perforated, plastic stencil is used in combination with special color compositions to attain high brilliance of color in the printed product, together with sharp definition of the minutest detail of the stencil design.

Yet another object of this invention is to provide a method of printing based on the combination of a perforated plastic stencil, means for holding the stencil, and paint compositions applicable through the stencil, which allows for high speed duplicating operations while producing a high quality product; such product giving no indication of having been produced by conventional duplicating procedures.

Other objects of this invention will in part be obvious and in part hereinafter pointed out.

In the drawing:

FIG. 1 is a longitudinal view of a stencil sheet prepared to carry out the method of the invention;

FIG. 2 is a perspective view of a stencil frame and stencil assembly embodying the invention;

FIG. 3 is a side view of the frame in a mounted position; and

FIG. 4 is a transverse sectional view of the frame on the line 44 of FIG. 2.

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There is available synthetic resin stencil sheets which are adapted to be perforated by suitable electric-a1 means to form a stencil design, as more particularly described in Patent 2,664,043. Such stencil sheets are carried on a backing layer and are perforated by the electrical means which includes means for scanning the original design carried on a rotating drum; the stencil sheet also being carried on a rotating drum, all as described in said Patent 2,664,043.

It has been found that such perforated plastic stencil sheet may be used in duplicating procedures wherein the stencil sheet is stretched on a frame; color compositions are forced through the perforations of the stretched sheet, to imprint fabric, paper or other bases. The imprinted designs thus produced exhibit high brilliance and fine details of the design.

Thus, as shown in FIG. 1, there is provided a nonfibrous, synthetic plastic stencil sheet 10, which has been electrically perforated in accordance with a selected master design. The stencil sheet 10 is carried on a paper or other suitable backing 11. The composite sheet and backing 1t 11 is formed along one transverse edge thereof with openings 12 for the purpose later appearing.

When stencil sheet has been electrically perforated to provide the desired stencil design thereon, the sheet 10 has the central portions of backing 11 removed to expose the stencil perforations on the underside thereof. The end portions of backing 11 at the opposite ends of sheet 10, may be retained.

The perforated stencil sheets 10 are adapted to be mounted on a printing frame 15, as shown in FIG. 2. Frame 15 is of rectangular shape, comprising longitudinally extending side bars 16 interconnected by cross members 17, 18. Bars 16 include portions 19, 20 which project at the opposite ends thereof beyond cross members 17, 18. End portions 19, 20 are formed with longitudinal slots 21, for the purpose hereinafter appearing.

A transversely extending locating rod 22 is mounted between the inner edges of side bars 16, rod 22 being spaced inwardly of cross member 17. Similarly, a second locating rod 22A is mounted between side bars 16 in spaced relation to cross member 18. The side bars 16 are provided on the underside with inwardly directed, longitudinally extending flange strips 23, for the purpose later appearing. Upstanding pins 24 are fixed in spaced relation on cross member 17 along the edge thereof adjacent the opening of frame 15; said pins 24 being adapted to pass through openings 12 in stencil sheet 10 when the stencil sheet is stretched on frame 15.

The side bars 16 are notched on their inner edges at the opposite ends thereof, as at 25 to allow the opposite ends of the stencil sheet 10 to be received between said side bars; the frame opening 15A being slightly narrower than the width of stencil sheet 10. The upper end of sheet 10 being mounted on pins 24, the intermediate portions of said sheet are passed beneath rods 22, 22A to locate the sheet on the underside of frame 15, closing opening 15a, with the marginal side portions of sheet 10 lying beneth flange strips 23.

The bottom edge 26 of sheet 10 is provided on opposite sides thereof with longitudinally projecting loops 26A to receive therethrough a transversely extending stretcher bar 27; the bottom edge 26 of sheet 10 being brought up between the lower notched portions 25 of side bars 16.

The opposite, projecting end portions 28 of bar 27 are disposed on the upper faces of side members 16 and are moved downwardly to render sheet 19 taut longitudinally in frame opening 15A. Clips 29 mounted on side bars 16 opposite cross member 18 are adapted to engage bar ends 28 to fix the same. Clips 29 may be of conventional frictional hold-down type, allowing for quick engagement or disengagement of stretcher bar 27.

Frame 15 is pivotally attached to a printing base 30, as shown in FIG. 3; base 30 being a rectangular, fiat, smooth surfaced panel or the like for receiving the cloth, paper or other material to be imprinted by way of stencil 10. Base 30 is provided on the underside thereof along the upper edge with a transversely extending batten 31. A pivot bar 32 is disposed in abutting relation to the transverse edge 33 of base 30' and is hingedly connected to batten 31 as at 34. Thumbscrews 35 are fixed on pivot bar 32 in an upstanding position on opposite ends thereof, said screws 35 being adapted to pass through the slots 21 on frame 15 to adjustably mount said frame on the pivot bar. Base 30 and its batten 31 may be located on a table support indicated at 36.

In using frame 15, the same may be tilted to a raised position relative to printing base 30, to allow the fabric, paper or other sheet, not shown, which is to be imprinted, to be mounted on base 39 in proper position to stencil sheet carried by frame 15. Suitable guides, not shown may be used to locate the sheet to be imprinted, on base 30.

The frame is now tilted downwardly to bring stencil sheet 10 into close contact with the sheet to be imprinted. Color composition is applied to the top surface of stencil sheet 10 and is squeegeed in a known manner, to force the same through the stencil perforations 10A to imprint the sheet beneath stencil 10. Flanges 23- keep color composition from leaking past the side edges of the stencil sheet.

When color changes are to be made, the previously applied, residual color may be quickly removed from the impervious surface of sheet 10, which is then merely wiped clean, thereby allowing a different color to be applied in the manner previously described.

Also, stencil sheet 10 may be quickly removed from frame 15, when no longer needed for printing, and may be stored in a flat, compact condition, until needed again. It will be apparent that changes of stencil sheets 10 on frame 15 may be made quickly through easy manipulation of the stretcher bar 27. The entire frame 15 with its stencil sheet 10 mounted thereon, may be reversed end to end and remounted on pivot bar 32 through bar slots 21 at the opposite ends of side bars 16 and thumbscrews 35. Further, the longitudinal posi tion of frame 15 relative to base 30 may be adjusted by means of slots 21.

It has been found that the plastic stencil sheet 10, which may be formed of vinyl copolymers, vinylidene copolymers, polystyrene or the like, is particularly effective, when used in conjunction with color compositions made up of a mixture of oil emulsion paints and water colors.

Thus, when from 5 to 15% by volume of water color is mixed with from 95 to 85% of an oil emulsion paint, the resultant color composition on application through the stencil sheet 10 dries quickly, produces high definition designs on cloth as well as paper, all without flushing or &

bleeding. The selected color composition makes possible high quality printing While insuring excellent production rates.

Furthermore, the admixture of Water color with the oil emulsion paint gives an enhanced brilliance to the imprinted colors, particularly when applied to fabrics of various weaves. Also, such color combination gives to the imprinted fabric a hand similar to that attained when printing fabric with a conventional engraved roller. Preferably, the water color is used in amounts of from 5 to about 10% by volume, the remainder being the oil emulsion paint.

The term water color as used herein, refers to the conventional and well known color made up of pigment, which may be inorganic or organic, in combination with a gum, such as gum Senegal; in a Water suspension, together with the usual filler, such as chalk, titanium dioxide or the like. Water colors usually further include retarders such as glycerin and stabilizers such as phenol or the like.

The term oil emulsion paint as used herein, refers to the conventional inorganic or organic pigment ground in oil and suspended in water, which may contain a stabilizer such as cholesterol or the like. A typical oil would be mineral oil, although other oils known in the art may be used.

As various changes might be made in the embodiments of the invention as herein described, without departing from the spirit of the invention; it is understood that all matter shown or described herein shall be deemed illustrative and not limiting except as set forth in the appended claim.

Having thus described my invention, I claim as new and desire to protect by Letters Patent:

A duplicating device comprising an open frame, a perforated synthetic plastic stencil sheet closing the opening in said frame, means on one end of said frame for detachably securing one end of said stencil sheet on the top surface of said one end of the frame, means on the other end of said frame for detachably securing the other end of said stencil sheet on the top surface of the other end of said frame while leaving the side edges of said stencil sheet in unsecured relation to the side edges of said frame, and means on said frame engageable with opposite end portions of said sheet for locating the major portion of said sheet between the end portions thereof below the bottom surfaces of the sides edges of said frame.

References Cited in the file of this patent UNITED STATES PATENTS 1,354,478 Gestetner Oct. 5, 1920 1,419,662 Erdle June 13, 1922 1,533,700 Dibble et al. Apr. 14, 1925 1,956,611 Besocke May 1, 1934 2,136,985 Stocker Nov. 15, 1938 2,566,919 Black et al. Sept. 4, 1951 2,664,043 Dalton Dec. 29, 1953 

